: This is a Stage la/lb Behavior Therapy Development Application to develop a secondary prevention intervention for adult drug court clients who do not have an identifiable substance use disorder. The drug court treatment model assumes that most drug offenders are addicts, and that substance use fuels their criminal activity. Accordingly, clients must satisfy an intensive regimen of treatment and supervisory obligations, including several hours per week of drug counseling, on-going judicial status hearings, and random weekly urine testing. However, recent research suggests that roughly one-third of drug court clients do not have a diagnosable or clinically significant substance use disorder. As such, these individuals may be best suited for a secondary prevention approach directed at interrupting the early acquisition of addictive behavior. Unfortunately, virtually all of the existing research on prevention programs for substance use has focused on children or adolescents, and we have been unable to locate any study of a prevention strategy designed for adult substance users who are not embedded in an educational institution. Over the past 18 months, we have identified the target population, reviewed the literature to identify potentially promising prevention strategies, identified the key elements of a prevention intervention, held focus groups with drug court clients and staff to gauge the acceptability of specific prevention strategies, pilot tested a secondary prevention package to assess its feasibility and acceptability, and assembled a multi- disciplinary panel of experts to help us identify the most promising elements to include in an intervention. Building on this foundation of work, this proposal has the following specific aims -- (1) finalize the content of the prevention intervention with the assistance of the expert panel; (2) manualize the prevention intervention and develop therapist-fidelity and client-adherence measures; and (3) estimate an effect size for the prevention intervention by conducting a small randomized pilot study (N=40) comparing the prevention intervention to standard drug court treatment, which will allow us to determine whether future Stage II research is warranted. [unreadable] [unreadable] [unreadable]